The present disclosure relates generally to the field of therapy for a reduction in severity of seizures in patients.
Approximately 3 million people in the US have epilepsy, of whom 10% to 20% have a form of epilepsy that is not well controlled with anti-epileptic drugs (i.e. drug refractory). Patients with drug refractory epilepsy may seek alternative solutions such as surgical resection, ketogenic diet and neuromodulation. Vagus nerve stimulation, or VNS Therapy®, is an FDA approved neuromodulation treatment that may be used as an adjunctive therapy to pharmacology and has been demonstrated to reduce seizure frequency in a multicenter, randomized controlled trial as well as in subsequent single center trials. A current, commercially available VNS Therapy utilizes an open loop stimulation paradigm (i.e. the stimulation is delivered using a predetermined duty cycle (i.e. “ON” and “OFF” times)) with parameters that are physician programmable (i.e. current amplitude, pulse width, frequency). In addition, VNS Therapy provides patients and caregivers with an opportunity to administer stimulation on demand during or just prior to a seizure via the use of a portable magnet. The use of such a magnet to manually activate on-demand stimulation has been reported to terminate or in some cases, reduce the severity of seizures. However, not all patients have the ability to apply the magnet before the onset of a seizure and/or experience an aura (i.e., an early warning of an impending clinical seizure).